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Biomedical subjects

C Weissmann

Publications and source records attributed to C Weissmann.

At least 145 records · Page 8Linked to original sources
PubMed1978

Comparison of cloned rabbit and mouse beta-globin genes showing strong evolutionary divergence of two homologous pairs of introns.

Cloned beta-globin genes of both mouse and rabbit each contain a large and a small intervening sequence (intron) of about equal length at precisely the same positions relative to the coding sequence. The homologous introns show some sequence similarity, particularly at the junctions with the coding sequence. They most probably arose from a common ancestral sequence and diverged substantially during evolution.

Animals↗
PubMed1978

Nucleotide sequence heterogeneity of an RNA phage population.

The nucleotide sequence of 32P-RNA from Q beta phage clones was sampled by two-dimensional polyacrylamide gel electrophoresis of the RNAase T1-resistant oligonucleotides (T1 fingerprinting). About 15% of the clones derived from a multiply passaged Q beta population showed fingerprint patterns which deviated from that of the RNA from the total population. All deviations examined could be attributed to one and, less frequently, to two or more nucleotide transitions. Since the fingerprinting technique allows the analysis of only about 10% of the RNA sequence, we estimate that each viable phage genome in a multiply passaged population differs in one to two positions from the "average" sequence of the parental population. Several deviant clones were tested by growth competition against a "wildtype" population, after 10-20 generations, the resulting phage showed the "wild-type" T1 fingerprint pattern. We propose that a Q beta phage population is in a dynamic equilibrium, with viable mutants arising at a high rate (Batschelet, Domingo and Weissmann, 1976; Domingo, Flavell and Weissmann, 1976) on the one hand, and being strongly selected against on the other. The genome of Q beta phage cannot be described as a defined unique structure, but rather as a weighted average of a large number of different individual sequences.

Base Sequence↗
PubMed1978

The intervening sequence of a mouse beta-globin gene is transcribed within the 15S beta-globin mRNA precursor.

Mouse beta-globin in encoded in a discontinuous structural gene interrupted by a 550-base pair intervening sequence of DNA. Correspondingly, the mature beta-globin mRNA appears to be synthesized via a 15S precursor, the length of which roughly equals the total length of the coding and intervening sequences of the beta-globin gene. Using the electron microscope to visualize hybrid structures formed between this gene and the purified 15S beta-globin mRNA precursor, we show that the intervening sequence is present within the larger precursor molecule. This finding suggests that the precursor mRNA is processed through the removal and rejoining of internal RNA sequences.

Cell Line↗